Crankpuller for Campagnolo cranks and many others (incl. Sugino, SR, Shimano). Designed to work with the same 15 mm closed wrench (the famous "Peanut Butter" wrench) used to remove or install the crank bolts from the bottom bracket. This was one of the tools included with the late 1960s and early 1970's Schwinn Paramounts. See photo of 1969 Paramount tool set included.